What happens when an electron falls to a lower energy level?

A 100 gram glass container contains 200 grams of water and 50.0 grams of ice all at 0°c. a 200 gram piece of lead at 100°c is ad

ASHA 777 [7]

$0 \; \textdegree{\text{C}}$

Explanation:

Assuming that the final (equilibrium) temperature of the system is above the melting point of ice, such that all ice in the container melts in this process thus

$E(\text{fusion}) = m(\text{ice}) \cdot L_{f}(\text{water}) = 66.74 \; \text{kJ}$ and
$m(\text{water, final}) = m(\text{water, initial}) + m(\text{ice, initial}) = 0.250 \; \text{kg}$

Let the final temperature of the system be $t \; \textdegree{\text{C}}$ . Thus $\Delta T (\text{water}) = \Delta T (\text{beaker}) = t(\text{initial}) - t_{0} = t \; \textdegree{\text{C}}$

$Q(\text{water}) &= &c(\text{water}) \cdot m(\text{water, final}) \cdot \Delta T (\text{water})= 1.047 \cdot t\; \text{kJ}$ (converted to kilojoules)
$Q(\text{container}) &= &c(\text{glass}) \cdot m(\text{container}) \cdot \Delta T (\text{container})= 0.0837 \cdot t \; \text{kJ}$
$Q(\text{lead}) &= &c(\text{lead}) \cdot m(\text{lead}) \cdot \Delta T (\text{lead})= 0.0255 \cdot (100 - t)\; \text{kJ}$

The fact that energy within this system (assuming proper insulation) conserves allows for the construction of an equation about variable $t$ .

$E(\text{absorbed} ) = E(\text{released})$

$E(\text{absorbed} ) = E(\text{fushion}) + Q(\text{water}) + Q(\text{container})$
$E(\text{released}) = Q(\text{lead})$

Confirm the uniformity of units, equate the two expressions and solve for $t$ :

$66.74 + 1.047 \cdot t + 0.0837 \cdot t = 0.0255 \cdot (80 - t)$

$t \approx -55.95\; \textdegree{\text{C}} < 0\; \textdegree{\text{C}}$ which goes against the initial assumption. Implying that the final temperature does <em>not</em> go above the melting point of water- i.e., $t \le 0 \; \textdegree{\text{C}}$ . However, there's no way for the temperature of the system to go below $0 \; \textdegree{\text{C}}$ ; doing so would require the removal of heat from the system which isn't possible under the given circumstance; the ice-water mixture experiences an addition of heat as the hot block of lead was added to the system.

The temperature of the system therefore remains at $0 \; \textdegree{\text{C}}$ ; the only macroscopic change in this process is expected to be observed as a slight variation in the ratio between the mass of liquid water and that of the ice in this system.

3 0

3 years ago

How does latitude affect climate?<br> Blast blast blast blast blast blast blast

cestrela7 [59]

Answer:

THANKS

Explanation:

There is a relationship between latitude and temperature around the world, as temperatures are typically warmer approaching the Equator and cooler approaching the Poles. There are variations, though, as other factors such as elevation, ocean currents, and precipitation affect climate patterns.

8 0

3 years ago

A balloon contains 2.0 L of air at 101.5 kPa. You squeeze the balloon to a volume of .75 L. What is the pressure of air on the i

Nataly_w [17]

You would use the formula for Boyle's Law:

(P1) (V1) = (P2) (V2)

(101.5) (2.0) = (P2?) (.75)

*P2 = 270kPa (You're allowed 2 significant figures)

P = Pressure

V = Volume

3 0

3 years ago

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Which of the following could be true of two species that have a competitve ralationship in the same ecosystems Help me out pleas

ankoles [38]

The answer is b. as a whole, the species is mutually beneficial to carry on each others traits and exist in the same ecosystem.

6 0

3 years ago

Read 2 more answers

Which statement describes a similarity between conductors and insulators?

Ivanshal [37]

Answer:

They can both be used in an electric circuit.

Explanation:

Though conductors and insulators are very different from each other but still they have a similarity that "they can both be used in an electric circuit".

Conductors are the material that allows electricity to flow and insulators have high resistance and do not allow electricity to flow.

Both conductors and insulators are used in an electric circuit as conductor is used in wires, batteries and bulb to flow current while insulators are used in insulation of wire, switches, plugs and etc. Combination of them makes the circuit shock free.

Hence, the correct answer is "They can both be used in an electric circuit."

4 0

3 years ago